Help with Task Scheduler Managed Wrapper

Hi, i have created a form in VS2012 with textboxes to enter starttime (as 00:00) , user, office and a datetimepicker to set a startdateof the scheduled task.

I am using the  Task Scheduler Managed Wrapper from http://taskscheduler.codeplex.com/discussions

I have a couple of issues with setting the task

I have this:

                        dateTimePicker1.Format = DateTimePickerFormat.Custom;
            dateTimePicker1.CustomFormat = "yyyy, MM, dd";
            string startdate = dateTimePicker1.Text;
           string username = TB_username.Text;
           string newsitecode = TB_newsitecode.Text;

Can i pass this into the timetrigger? I would like to set the task with text values provided by the starttime and by the datetimepicker

taskdDef.Triggers.Add(new TimeTrigger(new DateTime(2012, 12, 31)));

I tried as 
taskdDef.Triggers.Add(new TimeTrigger(new DateTime stardate)));
but it doesn't work.

Also if i try to use  2 arguments on 
taskdDef.Actions.Add(new ExecAction("c:\task.exe", "-user" + user + @" -office " + office));

but the arguments are created as:

System.Windows.Forms.TextBox, Text: user

I know i need to use user.Text to remove this but it stilll doesn't work, any ideas?

Thanks